Chicka Chicka Boom Boom by Bill Martin, Jr. and John Archambault, illustrated by Lois Ehlert, 1989.

This is an alphabet book for young children, but it’s not like most alphabet books.  Most alphabet books try to tie letters of the alphabet to words that young children know, to emphasize the sounds that the letters make, like in A, My Name is Alice or the letter-themed tongue twisters in Animalia.

In Chicka Chicka Boom Boom, the letters of the alphabet decide to climb to the top of a coconut tree.  (Why not?)  They go up the tree in alphabetical order.

But, by the time they reach the end of the alphabet, there are too many letters in the tree, and they all fall out.

The uppercase versions of the letters are the adults of the story, like parents and aunts and uncles, and they comfort the lowercase letters who fell out of the tree.

At the end of the book, the letter ‘a’ tries to convince the others to climb the tree again.

As I said, this book struck me as unusual for an alphabet book because it doesn’t try to tie any of the letters to associated words.  Mostly, it just emphasizes the order of the letters, first in the order that they go up the tree, and then in the order that they recover from falling out.

The story is told in rhyme, and the “Chicka Chicka Boom Boom” part is just sounds that fill out the story/rhyme, like it’s part of a song. At the end of the book, there’s a page with all of the letters of the alphabet, both upper and lowercase.

The book is currently available online through Internet Archive.